Thickened hydrocarbon compositions



3,114,710 THICKENED HYDROCAUN CGMPUSETIQNS George M. Calhoun, Berkeley,Calif., assignor to Shell Oil Company, New York, N.Y., a corporation ofDelaware No Drawing. Filed Feb. 1%, H60, fier. No. 7,7 81 lib Claims.(Cl. 252-325) This invention relates to improved liquid hydrocarboncompositions and to additives therefor. More particularly, the inventionrelates to gelled or grease-like hydrocarbon compositions.

In general, in order to prepare suitable greases from liquidhydrocarbons by thickening with soaps, such as stearates orhydroxy-stearates, certain petroleum fractions of particular viscosityranges and chemical composition are required. With very light petroleumfractions, such as gasoline, kerosene, or distillate fuel oil,conventional thickeners such as soaps are either ineffective or requiresuch large amounts or specific equipment and techniques for theirmanufacture so as to make their preparation impractical.

It is an object of the present invention to provide novel stable andimproved gels or grease-like compositions. It is a further object toprovide a gel or grease from liquid hydrocarbons of wide boiling range.It is a still further object of this invention to provide a gel orgrease from a light liquid petroleum base. It is a further object toprovide a novel class of compounds which impart beneficial antiwear andextreme pressure properties to liquid hydrocarbons. These and otherobjects of the invention will be apparent from the following detaileddescription thereof.

It has now been discovered that liquid hydrocarbon compositions areimproved with respect to wear-inhibiting and extreme pressure propertiesand may be transformed into stable gels or greases by incorporatingtherein a minor amount of an oil-soluble metal salt of a hydrocarbylthiomethyl phosphonic acid or monoester thereof. The acid portion of thepolyvalent metal salt has the general formula R1 X X131 XH (I) wherein Ris an oil-soluble hydrocarbyl group, such as an alkyl, aryl, aralkyl,alkaryl or cycloalkyl radical having at least 6 carbon atoms andpreferably is a C1048 alkyl radical, the R s are the same or differentgroups which may be hydrogen or a C alkyl radical and the Xs are oxygenor sulfur, preferably oxygen. The cationic portion of the salt is apolyvalent metal of variable or non-variable valence such as an alkalineearth metal, e.g., Ca, Mg, Ba, Sr, or another polyvalent metal such asCr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Al, or Sn, of which preferred ones areFe, Ni, Cu, Zn, Cd, and Al.

The anionic portions of these polyvalent metal salts which are preferredare anions of acids which have the formula H C 10-13 alkyl-S C Hi Pwhere R is the same as defined in (l) and preferably a C alkyl radical.The acidic compounds represented by the above formulas are prepared byreacting a mercaptan or mercaptide having at least 6 carbon atoms with ahalomethylphosphono compound such as chloromethylphosphonic acid orchloromethylphosphonate or their thio derivatives, in a suitablesolvent, such as an aqueous alcoholic solution, at reflux temperatureand under inert Patented Dec. 17, 1%63 ice conditions until the reactionis completed, which may require from 1 to about 5 days. The mercaptansinclude: aliphatic mercaptans, such as hexyl, octyl, decyl, dodecyl andoctadecyl mercaptans; cycloalkyl mercaptans, such as cyclohexylmercaptan and dicyclohexyl mercaptan; and aralkyl mercaptans, such asphenyldecyl mercaptan and benzyl mercaptan. Instead of the mercaptans,the corresponding mercaptides can be used such as the alkali metal,e.g., Na or K mercaptides. Suitable halomethylphosphono compoundsinclude chloromethylphosphonic acid, mono or dihydrocarbylchloromethylphosphonates, e.g., mono or dibutyl chloromethylphosphonate,mono or di-2-ethylhexyl chloromethylphosphonate, mono or diluarylchloromethylphosphonate, mono or diphenyl chloromethylphosphonate, monoor dicyclohexyl chloromethylphosphonate, mono or dibenzylchloromethylphosphonate, dibutyl chloromethyldithiophosphonate, diphenylchloromethyldithiophosphonate, dibutyl chloromethyltrithiophosphonate,and alkali metal salts such as Na and K salts of chioromethylphosphonicacid, Na and K salts of monobutyl chloromethylphosphonic acid, N a and Ksalts of rnonodecyl chloromethylphosphonic acid and the like.

A preferred method of making the thiomethylphosnates is to react asuitable mercapto compound, such as an alkali metal, e.g., Na or K,C1048 alkyl mercaptide with an alkali metal, e.g., Na or K, salt ofchloromethylphosphonic acid in an alcoholic solution under refluxconditions and under an inert atmosphere to form the alkali metal saltof an alkyl mercaptomethylphosphonic acid. The salt is then treated witha strong acid such as hydrochloric acid to spring free thealkylmercaptomethylphosphonic acid, which can be converted into thedesired polyvalent metal salts.

The following examples illustrate the preparation of the acid portion ofthe salt for use in accordance with the present invention.

EXAMPLE I Stoichiometric amounts of the potassium salt of decylmercaptan and monochloromethylphosphonic acid were dispersed in anaqueous solution of ethyl alcohol and the mixture was refluxed at 7 8 C.under a nitrogen atmosphere for about 1 day. The potassiumdeclymercaptomethylphosphonate was then treated with strong hydrochloricacid to spring free the phosphonic acid which was recovered byextraction with ether. The final product, decylmercaptomethylphosphonicacid, analyzed as follows:

Equivalent Weight First Both Hydro- Hydrogen gens Found 49.1 9.4 12.011.2 261 132 Expected 40.2 9.4 11.94 11. 54 268.3 134.1

EXAMPIJE II phonate, monobutyl dodecylmercaptomethyl acidthiophosphonate, monobutyl phenylmercaptomethyl acid phosphonate,monooctyl cyclohexylmercaptomethylthio acid thiophosphonate.

The above thiomethylphosphonic acids are converted to the neutral orbasic polyvalent metal salts by suitable means such as by neutralizingthe acid with an aqueous solution of sodium hydroxide or carbonate andmixing the sodium salt thus formed with an excess of an aqueous solutionof the desired polyvalent metal compounds such as a sulfate, nitrate,chloride, acetate or the like and removing the precipitated organicpolyvalent metal salt by suitable means, such as filtration,decantation, or extraction. The reaction is generally conducted atambient temperature, but may vary from, say, C. to 120 C.

The following examples illustrate the preparation of the polyvalentmetal salts of the invention.

EXAMPLE III Preparation of Basic Iron Salt of MonobutylDecylthiomethylphosphonale The product of Example II was neutralizedwith an aqueous solution of sodium hydroxide to which was added anexcess of an aqueous mixture of ferrous ammonium sulfate at ambienttemperature while constantly stirring the mixture. The ironthiophosphonate precipitated and the aqueous phase was removed bydecantation. The salt was purified by dissolving it in benzene,separating the benzene from insoluble material, water-washing, andstripping the benzene from the purified product. The end product was abasic iron phosphonate, which may be represented by the formula and theproduct analyzed as follows:

Percent Percent Fe S Percent P Found 7.1 Expected 7. 9

EXAMPLE IV Preparation of the Neutral Iron Salt of the Monoester ofExample II The neutral salt of the monobutyl decylthiomethyl phosphonatewas similarly prepared by following the general procedure of Example IIIin neutralizing the product The cadmium salt of mono-butyldecylthiomethylphosphonate was prepared by the procedure of Example I,using cadmium nitrate as the neutralizing agent. The salt was dissolvedin benzene and water-washed repeatedly and the solvents Were thenstripped off and the product analyzed as follows:

Percent Percent Percent Cd S P Found... 14. 7 8. 8.00 Ex pcctccL- 14. 838. 46 8. 18

EXAMPLE v1 Preparation of Zinc Salt of ZlJOnObutylDecylthz'omethylphosphonate The zinc salt of monobutyldecylthiomethylphosphonate was prepared following the procedure ofExample V using zinc chloride as the neutralizing agent and the productanalyzed as follows:

The following illustrate additional metal salts of this invention: Cr,Mn, Fe, Co, Ni, Cu, Al and Zn salts of octylmercaptomethylphosphonicacid, dodecylmercaptomethylphosphonic acid,cyclohexylmercaptomethylphosphonic acid, benzylmercaptomethylphosphonicacid, phenylmercaptomethylphosphonic acid, butyl decylmercaptomethylacid phosphonate, phenyl decylmercaptomethyl acid phosphonate,monotbiobutyl dodecylmercaptomethyl acid phosphonate, monobutylphenylmercaptomethyl acid phosphonate, monothiooctylcyclohexylmercaptomethyl acid thiophosphonate and the like.

The additives of this invention are believed to be novel compounds. Theyare soluble in various hydrocarbons and mixtures thereof of wide boilingrange. These are useful therein for varied purposes and generally inamounts of from about 0.0001% to about 10%, preferably from 0.001% toabout 5.0% by weight.

The polyvalent metal salts of mercaptomethylphosphono compounds of thisinvention are outstanding additives for improving, or gelling orthickening various liquid hydrocarbon products, such as natural andsynthetic hydrocarbon lubricating oils, fuels (gasoline, kerosene, gasoil, burner fuel oil), 'slushing oils and various industrial oils, e.g.,metal working and drawing oils, quenching oils, textile oils, hydraulicoils, dielectric compositions and other industrial oils. vThey areparticularly outstanding when added in small amounts to hydrocarbonfuels such as gasoline or kerosene or lubricating oils and lubricatingcompositions in imparting extreme pressure and anti-wear properties tosuch materials. These additives are particularly useful as antioxidantsand as gelling agents for gasoline, fuel oils, and other light oilproducts.

The addition of 2% of the additive of Example III to kerosene at ambienttemperature formed a solid fuel composition capableof withstanding hightemperatures, above 350 F., without essential change in structure orstability.

The addition of 400 parts per million of the additive of Example III togasoline increased the viscosity of the gasoline 70%.

The addition of 1% of additive of Example IV to JP-4 jet fuel yields aheavy oil of SAE viscosity and the addition of 1% additive of ExampleIII to JP-4 fuel yields a sticky gel which can be burned withoutcollapsing.

The addition of only 1% of the additive of Example VI to an SAE 30refined mineral oil produced a grease.

The addition of 2% of neutral A1 salt of decylthiomethylphosphonic acidto an SAE 30 refined mineral oil formed a grease.

Greases are also formed by addition to mineral oil (at ambienttemperature) of from 1% to 5% of any of the following salts alone or inmixtures thereof:

Cd, Zn, Al, Fe, Sn, Mn, Mg, Ca, Ba, salts ofdodecylthiomercaptophosphonic acid, benzylthiomethylphosphonic acid,butyl dodecylthiomethyl acid phosphonate, cyclohexyl decylthiomethylacid phosphonate, butyl decylthiomethyl acid thiophosphonate.

I claim as my invention:

1. A hydrocarbon liquid composition comprising a major amount of aliquid hydrocarbon and a minor amount, sufiicient to impart extremepressure properties to the liquid hydrocarbon and gel it to a greasestructure of an oil-soluble polyvalent metal salt of a hydrocarbylmercaptomethylphosphono compound having the general formula wherein R isan oil-soluble C hydrocarbyl radical, the R s are selected independentlyfrom the group consisting of hydrogen and C alkyl radical, and X is achalcogen having an atomic number from 8 to 16.

2. The composition of claim 1 wherein R is a C alkyl radical, X isoxygen.

3. The composition of claim 1 wherein R is a C alkyl radical, each R ishydrogen and X is oxygen.

4. The composition of claim 1 wherein R is a C1048 alkyl radical, and Xis sulfur.

5. A liquid hydrocarbon composition comprising a major amount of aliquid hydrocarbon and a minor amount, sufficient to impart extremepressure properties to the hydrocarbon liquid and gel it to a greasestructure, of a polyvalent metal salt of C alkylmercaptomethylphosphonicacid.

6. A liquid hydrocarbon composition comprising a major amount of aliquid hydrocarbon and a minor amount, suificient to impart extremepressure properties to the liquid hydrocarbon and gel it to a greasestructure, of a polyvalent metal salt of a monoestcr of C1048alkylmercaptomethylphosphonic acid.

7. A liquid hydrocarbon fuel composition comprising a major amount of aliquid hydrocarbon and a minor amount, sufficient to increase theviscosity of the fuel, of a polyvalent metal salt of C1048alkylmercaptomethylphosphonic acid.

8. A liquid hydrocarbon fuel composition comprising a major amount of aliquid hydrocarbon and a minor amount, sufficient to thicken the fuel toa solid, of a basic polyvalent metal salt ofdecylmercaptomethylphosphonic acid, the metal portion of the salt beingselected from the group consisting of Zn, Cd, Fe and Al.

9. A liquid hydrocarbon fuel composition comprising a major amount of aliquid hydrocarbon and a minor amount, sufficient to thicken the fuel toa solid, of a neutral polyvalent metal salt ofdecylmercaptomethylphosphonic acid, the metal portion of the salt beingselected from the group consisting of Zn, Cd, Fe and A1.

10. A gasoline containing a minor amount, suficient to thicken thegasoline to a solid, of iron salt of decylmercaptornethylphosphonicacid.

References Cited in the file of this patent UNITED STATES PATENTS2,795,492 Aylesworth et al June 11, 1957 2,838,555 Goldsmith June 10,1958 2,838,557 Verley June 10, 1953 2,854,468 Max Sept. 30, 19582,881,201 Schrader Apr. 7, 1959 2,911,292 Baldeschwieler Nov. 3, 19592,947,693 Boyle et al Aug. 2, 1960 2,971,019 Ladd et al Feb. 7, 19612,991,244 Pattenden et a1. July 4, 1961 FOREIGN PATENTS 751,755 GreatBritain July 4, 1956

1. A HYDROCARBON LIQUID COMPOSITION COMPRISING A MAJOR AMOUNT OF ALIQUID HYDROCARBON AND A MINOR AMOUNT, SUFFICIENT TO IMPART EXTREMEPRESSURE PROPERTIES TO THE LIQUID HYDROCARBON AND GEL IT TO A GREASESTRUCTURE OF AN OIL-SOLUBLE POLYVALENT METAL SALT OF A HYDROCARBYLMERCAPTOMETHYLPHOSPHONO COMPOUND HAVING THE GENERAL FORMULA